diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index e13ca3d7..ecbc03d2 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -1311,7 +1311,7 @@ and THREAD.  The next query is THREAD alone, and serves as a
 fallback if the prior matches no messages."
   (let (queries)
     (push (list thread) queries)
-    (if context (push (list thread "and (" context ")") queries))
+    (if context (push (list "(" thread ") and (" context ")") queries))
     queries))
 
 (defun notmuch-show--build-buffer (&optional state)